Plasma (or serum) cystatin C has been proposed as a marker for the glomerular filtration rate, a measure of the capacity of the kidneys to filter plasma (GFR). Several studies, as well as one meta-analysis, have suggested that it is superior to serum creatinine for estimation of GFR.
The IFCC working group for the standardisation of cystatin C has, in collaboration with the IRMM, prepared a candidate reference material (RM) for cystatin C. here the results from a preliminary study, performed in order to optimise the design of a planned large-scale commutability study, are presented.